question about A3000 and overclocking.

jvdbossc

HypnusBE
Joined
Nov 11, 2009
Posts
3,326
Country
Belgium
Region
Antwerp (province)
Is it possible to overclock the A3000? I can't find anything exept an fpu overclock, not cpu.:blink: I quite like the machine and not looking for an acelerator, but the 25 mhz is a little to far of my main reference machine: A1200, 68030 at 50 mhz..;) So I was thinking @ 33 mhz ? Just change the chrystal or not?
 

LTAC

New member
AmiBayer
Joined
Mar 21, 2009
Posts
2,527
Country
FRANCE
Region
South of PARIS
Is it possible to overclock the A3000? I can't find anything exept an fpu overclock, not cpu.:blink: I quite like the machine and not looking for an acelerator, but the 25 mhz is a little to far of my main reference machine: A1200, 68030 at 50 mhz..;) So I was thinking @ 33 mhz ? Just change the chrystal or not?

On an A3000@25Mhz: overclocking only for the FPU:
http://www.amiga.org/forums/showthread.php?t=50514
 

keropi

Active member
VIP
Joined
Dec 5, 2007
Posts
7,144
Country
Greece
Region
Ioannina
I am almost sure that if you oc the cpu (and thus it's bus) then you are going to make a mess on a bunch of other buses since all use the same crystal... so you would need to set an external clock but with the onboard cpu, which is pretty much almost impossible or too much work...
 

jvdbossc

HypnusBE
Joined
Nov 11, 2009
Posts
3,326
Country
Belgium
Region
Antwerp (province)
@LTAC, Thanks for looking..

@Keropi, so you mean changing the crystal means overclocking every other card in the system ?
 

keropi

Active member
VIP
Joined
Dec 5, 2007
Posts
7,144
Country
Greece
Region
Ioannina
yes, I am pretty sure you will also change the chipset timing, the zorro bus timing and so on... that is why when you install an accelerator you have to adjust jumpers from internal to external clock for the cpu...
 

AndyLandy

Acceleration!
Treasurer
Joined
Aug 29, 2009
Posts
9,898
Country
UK
Region
Southampton
Maybe you can do something clever with an A3630 CPU card, instead of messing with the on-board CPU. A3630s are fairly cheap, although I think they might have the same problems.

Alternatively, you can probably try and acquire an '030/50 accelerator for the machine.
 

jvdbossc

HypnusBE
Joined
Nov 11, 2009
Posts
3,326
Country
Belgium
Region
Antwerp (province)
@Andy, I have that cpu card yes, you have a good memory, it has no fpu however. I did not bother to sell it... But it takes it clock from the A4000 motherboard, so probably the same on A 3000.

Another problem would be the kickstart, it expects the FPU was told to me. So a 3.1 rom would be another needed item. Mmm Might go for that... The A3000 does not run games/demo's properly, even with the right kick, so upgrading the rom instead of kicking to 2.X and then skicking to 3.1 might be good idea afterall.



ps: I did not forget about our PM, but they don't respond none of three.:(

---------- Post added at 08:27 ---------- Previous post was at 08:04 ----------

I've send vesalia a mail about the 3.1 rom they claim to sell for the A3000, if it work's with my type of machine..:ninja:

The soft-kicking lost it's magic after the no run games and demo's...
 

colmiga

Still tinkering with Amiga's
AmiBayer
Joined
Feb 22, 2010
Posts
65
Country
Australia
Region
Brisbane
@Andy, I have that cpu card yes, you have a good memory, it has no fpu however. I did not bother to sell it... But it takes it clock from the A4000 motherboard, so probably the same on A 3000.

According to this, the 3630 has it's own crystal on the card so it would be possible to change the clock without messing with the motherboard timings. It also has a socket for an FPU.

Another problem would be the kickstart, it expects the FPU was told to me. So a 3.1 rom would be another needed item. Mmm Might go for that... The A3000 does not run games/demo's properly, even with the right kick, so upgrading the rom instead of kicking to 2.X and then skicking to 3.1 might be good idea afterall.
The A3000 Kickstart ROM does not require an FPU to function. It however does need at least a 68020 CPU.

I've send vesalia a mail about the 3.1 rom they claim to sell for the A3000, if it work's with my type of machine..:ninja:

The soft-kicking lost it's magic after the no run games and demo's...
A real 3.1 Kickstart is a great investment for any Amiga you wish to use seriously, you won't regret it. If you have no luck with Vesalia you could try posting a wanted ad here for a set.
 

jvdbossc

HypnusBE
Joined
Nov 11, 2009
Posts
3,326
Country
Belgium
Region
Antwerp (province)
Colmiga and others thanks a lot! :)

So to do list is:

1) Get the workbench 3.1 roms.

2) Get the dill crystal and solder it on the card. You are sure it is not for the FPU?

3) Look for the right jumpers on the A3000. If it proves enough mhz, then buy an FPU
 

keropi

Active member
VIP
Joined
Dec 5, 2007
Posts
7,144
Country
Greece
Region
Ioannina
I would like to pin-point that the A3630 which is designed for the A4000 does not have the cpu bus clock on a seperate "line". This card was designed for the A4000 and when used in one you need to set the clock jumpers to "internal" position. Imagine that as the same hardware and integration like on the A3000 , just on a seperate board. Overclocking that would cause issues with the other components...
 

jvdbossc

HypnusBE
Joined
Nov 11, 2009
Posts
3,326
Country
Belgium
Region
Antwerp (province)
So Keropi, this means, Overclocking the unit, makes it dangerous no matter what, ... So I'll have to keep it moderate..:whistle:
 

keropi

Active member
VIP
Joined
Dec 5, 2007
Posts
7,144
Country
Greece
Region
Ioannina
yep... you can only safelly oc cards with their own cpu clock... anything that needs the clock jumpers set to "external" can be oc'ed...
 

rkauer

Amiga fanboy
Joined
Dec 17, 2007
Posts
10,337
Country
Brazil
Region
São Leopoldo, RS
Soft-kick a kickstart image on anything than the original on-board 030 when the 1.4 ROM is hooked will make the A3000 not boot at all.

Using a real 3.1 ROM may cure the problem if you want to use an A3640 (some A3640 will not work in some A3000 models, no matter what).

On A3000 with DMAC04 - Ramsey07 you can use any A3640 (but 3.0 versions), but still you need kickstart 2.0/3.1 in ROM (with ROM 1.4 will not boot at all).

Of course you can overclock the onboard 030, all you need is to lift the clock pin and install a crystal somewhere to feed it. But I guess the machine will be unstable or even slower than it was due synchronizing problems with the chipset.
 
Top Bottom